硬磁/反铁磁交换耦合对反铁磁FeMn稳定性影响研究

摘要

采用磁控溅射方法在SiO2基体上制备了FePt/FeMn/NiFe/Ta多层膜样品,通过FeMn/NiFe双层膜交换偏置的变化研究了硬磁FePt不同磁化状态对反铁磁层FeMn的影响。实验表明,磁化了的L10相FePt能使FeMn在较薄的情况下（4.5nm）对NiFe产生比较强的交换偏置;而未被磁化的FePt对FeMn/NiFe交换偏置影响并不明显。认为更薄的反铁磁层对另外的铁磁层产生交换偏置是由于硬磁与反铁磁的界面交换耦合作用能增强反铁磁的稳定性。%The FePt/FeMn/NiFe/Ta multilayers were deposited on the SiO2 substrate by using magnetron sputtering system.The effect of hard magnet FePt on the thermal stability of antiferromagnet FeMn had been studied through the variations of exchange coupling between the FeMn and NiFe bilayers.It was found that the L10 phase of FePt makes thin FeMn pin NiFe well and there is no clear effect on the FeMn/NiFe exchange bias when FePt not magnetized.We attributed this to that the exchange coupling between hard magnet and the antiferromagnet can enhance the anisotropy energy of the antiferromagnet.